Aux 2 Unit 7 Quiz 1

Correct Answer:
B) The generators may trip due to a phase mismatch

Explanation:
Closing the circuit breaker when the generators are out of phase can cause a significant phase angle difference, resulting in a large surge of current that can trip protection systems or damage the generators.

Correct Answer:
C) High mechanical stress and potential damage to the rotor and shaft

Explanation:
Connecting generators out of phase can cause mechanical shock due to sudden torque changes, potentially damaging the rotors, shafts, or other mechanical components.

Correct Answer:
B) To avoid mechanical torque shock and electrical surges

Explanation:
If the phases are not aligned when the circuit breaker is closed, the resulting phase mismatch can cause mechanical torque shock and electrical surges that may damage the generators or associated equipment.

Correct Answer:
C) The overall system voltage may decrease

Explanation:
Reducing the excitation of one generator can lead to a decrease in the system’s overall voltage because there is less reactive power being supplied to support the voltage.

Correct Answer:
B) The generation of a high inrush current

Explanation:
Closing the circuit breaker while the generators are out of phase can create a significant inrush current as the system attempts to correct the phase difference, potentially causing damage or tripping the protective devices.

Correct Answer:
B) The generator with reduced excitation supplies less reactive power, and the other generator compensates

Explanation:
When the excitation of one generator is reduced, it supplies less reactive power, which leads to the other generator compensating by supplying more reactive power to maintain system stability.

Correct Answer:
B) The generator’s reactive power output decreases

Explanation:
Reducing the excitation of a generator decreases its reactive power output because the reduced field current weakens the magnetic field, affecting the ability to supply reactive power.